This question is for a 94 pontiac grand-am GT 3.1L. I am failing NOX by .4! I have replaced my cat, o2 sensor, and digital egr. I had a recent tune-up. And still I can't seem to pass freaking emissions! All that crap got me about .8 off my nox. What do I ned to do to pass?

 

If you haven't try driving around for at least 20 mins before going to the test. This will help clean the engine out a little.

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'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
3" Hooker CatBack w/Aero Chamber muffler
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
3:73 Posi
Rebuilt 700R4
B&M Megashifter, 5" Autometer Tach w/shift lite

 

Yeah I tried that I drove for a half hour before and then sat in line for an hour. The car was running the whole time.

 

You're probably running too lean, especially with the car warmed up. If you have some wiggle room with the CO and HC, drive that sucker in there as cold as possible to be tested.

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1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, MSD coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley module, ported plenum,
Ported Daytona Yellow stock base, Moroso valve covers, other stuff,
Streetdampr, Ruger P95DC, hot wife, new oil filter, !cats, !TBC, !AIR.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."

 

I pass the other two test by a ton. It's just NOX that I am failing by .4! Everything else is way low. I am begining to feel like This testing facility is ripping me off! Is there some place I could report them to?